1. Field of the Invention
This invention relates to integratedcircuits which in response to a variable DC input voltage produce a stable output DC voltage.
2. Description of the Prior Art
There are a variety of applications where stable DC reference voltages are needed. For example, charge-coupled (CCD) devices often require five or six stable DC voltages. In CCD devices, these voltages operate gate electrodes and a reset gate which resets the floating diffusion of an output diode. Often these voltages are provided by off-chip circuitry. For purpose of this disclosure, when an electrical circuit is fabricated on or within a substrate, it will be referred to as an integrated-circuit. A chip includes a substrate and all the electrical circuits fabricated on it. Off-chip circuits generally add to the overall system cost and complexity while reducing system reliability. There are a number of advantages for providing an integrated-circuit for producing a stable DC voltage. Unfortunately, such circuits can include a number of active elements and consume a relatively large amount of chip area.
The object of this invention is to provide an integrated-circuit for producing a stable DC voltage and which can be used on-chip and which uses very little chip area and consumes a relatively small amount of power.